Starter for engines



t. l 0c 927 M. B. JACKSON STARTER FOR ENGINES Filed Sept. 10, 1925 mveu'run.

Patented Oct. 25, 1927.

unrrno STATES MAUNSELL B. JACKSON, 01? TGRONTO, ONTARIO, GANAIDA.

STARTER FOR ENGINES.

Application filed September This invention relates to starters for internal combustion engines, of the type in which a starter pinion is threaded on a starter shaft. The object of the present invention is to provide a simple starter in which the possibility of the starter pinion and gear teeth becoming damaged while they are being meshed is reduced to a minimum. Other objects I have in mind will hereinafter .ap pear.

I attain my object by threading the starter pinion on its shaft so it will have a limited rotary movement relative to the thread on the shaft by providing means independent of the thread on the shaft for axially moving the pinion into mesh with the gear, the thread being used to more fully mesh the pinion with the and to form a rotary drive connection with the shaft when the pinion is in mesh with the gear, a further function of the thread being to carry the pinion out of mesh with the gear when the latter drives the pinion. The construction of my starter is hereinafter fully described and i lustrated in the accompanying drawings in which- Fig. l is a longitudinal section of the starter showing the pinion in its inoperative position;

Fig. 2 a sectional detail of the sprlng catch for releasably locking the pinion in its in operative position;

Fig. 3 a cross section of the p nion and shaft; and

Fig. l a cross section on the line H in Fig. 1.

In the drawings like reference numerals indicate corresponding parts in the different figures.

1 is an extended armature shaft of an electrio motor 13 (only partly shown). On the end 1 of the shaft is secured a sleeve 2 having a long pitched triple thread 2 formed thereon and on the outer end of the sleeve is secured a collar 3. An annular member 4 formed of fiat spring material is preferably secured on the inner face of the collar. A lip t" formed on the member is adapted to be received in a groove 3 formed in the side of the collar 3 and is retained therein by means of the inwardly directed flange formed on a band 5 passed round the periphcry of the collar 3 and secured thereto. The member l is provided with a cam-shaped portion 4: which is free of the band 5 and extends partly round the shaft 1 at an angle 10,, 1925. 5eria1 No. 55,563.

to the .axis thereof. It will be noted that the pitch of the helical portion 4P is less than the pitch of the threads 2 fora purpose which will hereinafter appear.

A pinion 6 loosely threaded on the sleeve 2 is adapted to be axially moved into and out of mesh with a gear 7 connected with the crankshaft of an engine (not shown) the common practice being to secure this gear to the engine fly wheel. An axially directed projection G is preferably carried by the pinion and this projection is normally in contact with the low portion of the camshaped member 4. As hereinbefore men tioned the pinion is loosely threaded on the sleeve which permits a limited rotary movement of the pinion threads relative to the sleeve threads which permits the helical portion P to be rotated relative to the projection 6 which produces a pressure on the latter tending to axially move the pinion into mesh with the gear. In other words the pinion threads are normally in contact with the sides a of the shaft threads 2* and when the shaft is set in motion the threads 2 run ahead of the pinion threads. The helical member also runs ahead of the projection 6, due to the inertia of the pinion, so that the helical portion forces the pinion along the shaft. If the pinion teeth enter between the engine gear teeth the latter hold the pinion from rotation and the sides 6 of the shaft threads engage the pinion threads to axially move the pinion farther along the shaft. The threads also form a rotary drive connection between the shaft and pinion to drive the gear when the axial movement of the pinion is stopped as hereinafter described.

If the teeth of the pinion and gear meet end to end, when the former is being axially moved by the helical portion 4 into mesh with the gear, the axial movement of the pinion towards the gear will be stopped but the rotary movement of the shaft relative to the pinion will continue so that the normally high or free end of the helical portion 4 will be pressed back until the sides 5 of shaft threads contact with the pinion threads and rotate the pinion teeth sufficiently to clear the teeth of the gear. The helical portion is then free to spring back and force the pinion axially of the shaft and into mesh with the gear. By employing long pitched threads on the shaft and pinion the force tending to move the pinion rotarily on the shaft is greater than the force tending to move it out of mesh with the gear. In this connection it will be notedthat the pinion threads are first rotated relative to the shaft threads to bring the former into engagement with the sides a of the shaft threads so that the projection 6 will clear the free end of the helical portion 41* when it is being returned to its normal position.

The sleeve 2 is provided with a slot adapt ed to receive a spring finger 8 formed on a washer 8 carried on the shaft at the inner end ofthe sleeve 2. This finger is provided 7 with a slight projection 8 see Fig. 2, adapted to normally engage the pinion to releasably hold it from accidental contact with the gear. The projection is depressed into the 7 slot by the pinion when force is applied to the latter to move it axially of the shaft.

l/Vhen the pinion is meshed with the gear 7 as hereinbefore described its axial movement islimited by a spring cushioned abutment formed by asliding bushing 9 and springs 10 and 11. The spring '10 is longer than the spring 11 and is disposed thereon, the spring 11 being disposed on the shaft 1. One end of each spring engages a disk 12 carried by the shaft and the opposite end of the spring 10 engages the bushing 9 to normally hold it against the washer 8 Referring to Fig. 1, it will be noted that the pinion 6 will be substantially fully meshed with the gear 7 before it engages the bushing 9 so that the springs 9 or'lO do not retard the axial movement of the pinion until after it is meshed with the gear. When the pinion engages the bushing 9, the spring 10 is first compressed and then the spring 11 is picked up and slightly compressed to limit the axial movement of the pinion. The bushing 9 is slidably mounted in a bearing 13 carried by the motor 13. a

/Vhat I claim is: 1. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the comhina tion of starter mechanism including a shaft; a starter pinion threaded on the shaft,'the pinion having a limited rotary movement relative to the thread, the said thread serving to rotate the pinion if the'teeth on the lattermeet end to end with the teeth on the gear; and means independent of the thread for axially moving the pinion whenthe teeth of the latter are rotated relative to the teeth of the gear sufficiently to clear, the sa1d means normally having'no tendency to move the pinion axially.

2. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of starter mechanism including a shaft; a starter pinion threaded on the shaft, the

pinion having a limited rotary movement relative to the thread, the said thread serving to rotate the pinion if the teeth on the latter meet end to end with the teeth on the gear; and means including a cam shaped member adapted to axially move the pinion when the teeth of the latter are rotated relative to the teeth of the gear sufiicientlyto clear. I

3. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of starter mechanism including a shaft;

a starter pinion threaded on the shaft, the V pinion having a limited rotary movement relative to the thread, the said thread serving to rotate the pinion if the teeth on the latter meet end-to end with the teeth on the gear; and means including a cam shaped springmember adapted to axially move the pinion when the teeth of the latter are rotated relative to the teeth of the gear suificiently to clear. r

4. In a starter for use with an internal con'ibustion engine having a gear adapted to rotate the crankshaft thereof, the combination of starter mechanism including a shaft; a starter pinion threaded on the shaft, the pinion having a limited rotary movement relative to the thread; and a spring member "carried by the shaft and having high and low portions, the low portion being normally in contact with the pinion and the high portion being adapted to yieldingly apply axial pressure tothe pinion, if the teeth on the latter meet end to end with the teeth on the gear, to force the pinion into mesh with the gear when the teeth of the former are rotated relative to the teeth of the latter sufiiciently to clear.

5. In a starter for use with an internal combustion engine having a gear adapted to rotate the'crankshaft thereof, the combination of starter mechanism including a shaft; a starter pinion threaded on the shaft, the said thread serving to rotate the pinion if the teeth on the latter meet end to end with the teeth on the gear; and a cam shaped member carried by the shaft and adapted to engage the pinion, the said member and pinion having a limited rotary movement relative to one another whereby an axial movement of the pinion is effected.

6. In. a starter for use with aninternal combustion engine having a gear adapted to rotate the crankshaft thereof, the combi- Ill nation of starter mechanism including a shaft; a starter pinion threaded on the shaft, the said thread serving to rotate the pinion if the teeth on the latter meet end to end with the teeth on. the gear; and a resilient cam shaped "member carried by the shaft and adapted to engage the pinion, the said mem her and pinion having .a limited rotary movement relative to one another whereby an axial movement of the pinion is effected.

7. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of starter mechanism including a shaft; a starter pinion threaded on the shaft, the pinion having a limited rotary movement relative to the thread, the said thread serving to rotate the pinion if the teeth on the latter meet end to end with the teeth on the gear; and a spring member carried by the shaft having high and low portions, the low portion being normally in contact with the pinion and the high portion being adapted to apply axial pressure to the pinion by a relative rotary movement of the shaft and pinion when the shaft is set in motion and to yieldingly engage the pinion to force it into mesh with the gear when the teeth of the pinion are rotated sufficiently to clear the teeth of the gear.

8. in a starter for use with an internal combustion engine, the combination of a shaft having a long pitched thread; a pinion threaded on the shaft and having a limited rotary movement relative to the thread; and a helical member having a short pitch and carried by the shaft for axially moving the pinion towards its starting position by a relative rotary movement of the pinion and shaft when the latter is set in motion.

9. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of a starter mechanism including a shaft having a long pitched thread; a starter pinion threaded on the shaft and having a limited rotary movement relative to the thread, the said thread serving to rotate the pinion if the teeth on the latter meet end to end with the teeth on the gear; a helical spring member having a short pitch and carried by the shaft for axially moving the pinion into mesh with the gear, the said spring member being adapted to yieldingly engage the pinion while it is being rotated to force it into mesh with the gear when the teeth of the pinion are rotated sufficiently to clear the teeth of the gear.

10. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of a starter mechanism including a shaft; a starter pinion threaded on the shaft and having a limited rotary movement relative to the thread, the said thread serving to rotate the pinionif the teeth on the latter meet end to end with the teeth on the gear; a cam shaped member carried by the shaft and having high and low surfaces, tae pinion having a rearwardly extending projection normally in contact with the said low portion and adapted to be engaged by the high portion to axially move the pinion by a relative rotary movement of the shaft and pinion when the shaft is set in motion, the said member also being adapted to engage the pinion while it is being rotated to force it into mesh with the gear when the teeth of the pinion are rotated sutliciently to clear the teeth of the gear.

11. In a starter for use with an internal combustion engine having a gear adaptezfl to rotate the crankshaft thereof, the combina tion of starter mechanism including a shaft; a starter pinion threaded on the shaft; and means including a plurality of coiled springs for limiting the axial movement of the pinion in its meshed position, the springs being concentric and one spring being longer than the other whereby it is engaged first.

12. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of starter mechanism including a shaft; a starter pinion threaded on the shaft; and means including a plurality of coiled springs normally disengaged from the pinion and adapted to limit the axial movement of the pinion in its meshed position, the springs eing concentric and one spring being longer than the other whereby it is engaged first,

13. In a starter for use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combina tion of starter mechanism including a shaft having a long pitched thread; a starter pinion threaded on the shaft, the pinion having alimited rotary movement relative to the thread, the said thread serving to rotate the pinion if the teeth on the latter meet end to end With the teeth on the gear; and means independent of the thread for axially moving the pinion When the teeth of the latter are rotated relative to the teeth of the gear sufficiently to clear, the said means being adapted to be brought into operative position only by a relative rotary movement of the pinion and shaft when the latter is set in motion.

14:. In a starter for use With an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of starter mechanism including a shaft; a starter pinion threaded on the shaft, the pinion having a limited rotary movement relative to the thread; and a spring member carried by one of the said shaft and pinion parts and having high and low portions, the low portion being normally in contact with the other of the said shaft and pinion parts ill) and the high portion being adapted to tend to move the pinion axially of the shaft, if the teeth in the latter meet end to end with the teeth on the gear, toforce the pinion into meshwith the gear when the teeth of the former are rotated relative to the'teeth of the latter sufliciently to clear.

15. In a starter for'use with an internal combustion engine having a gear adapted to rotate the crankshaft thereof, the combination of starter mechanism including a shaft; :1 starter pinion threaded on the shaft, the said thread serving to rotate the pinion if the teeth on the latter meet end'to end with the teeth on the gear; and a cam shaped member carriedby one of the said shaft and pinion parts and adapted to engage the other of the said shaft and pinion parts, the said member and its said engaging part having a limited rotary movement relative to one another whereby an axial movement of the pinion is effected. p

16. In a starter for use with an internal combustion engine having a gear adapted to rotate'the crankshaft thereof, the combination of starter mechanism including a shaft; a starter pinion threaded on the shaft, the said thread serving to rotate the pinion if the teeth on the latter meet end to end with the teeth on the gear; and a resilient cam shaped member carried by one of thesaid shaft and pinion parts and adapted to engage the other of-the said shaft and pinion parts, the said memberand its said engaging part having a.

" limited rotary movement relative to one another whereby an axial movement of the pinion'is effected.

17. In a starter for use with an internal combustion engine, the combination of a shaft having a long pitched thread; a pinion threaded on the shaft and havin a limited rotary movement relative to the thread; and a helical member having a short pitch and carried by one of the said shaft and pinion parts for axially moving the pinion towards its starting position by a relative rotary movement of the pinion and shaft when the latter is set in motion. 7 I

18. An engine starter drive mechanism including a'rotatable shaft; a starter pinion mounted thereon for rotary movement therewith and for longitudinal movement thereof to mesh with a gear of the engine to be started, theshaft serving to rotate the pinion if the teeth on the latter meet end to end with the teeth on the gear; and a cam shaped member carried by one of the said shaft and pinion parts and adapted to engage the other of the said shaft and pinion parts, the said member and its said engaging part having a limited rotary movement relative to one another whereby such longitudinal movement of the pinion is caused.

latter are rotated relative to the teeth of the gear sufficiently to clear.

Signed at Toronto, Canada, this 4th day of Sept. 1925.

MAUNSELL B. JACKSON. 

